Long distance (1.4 μm) interaction of two different InAs/GaAs quantum dots in a photonic crystal microcavity is observed. Simultaneous coupling of both quantum dots to the cavity is demonstrated by Purcell effect measurements. Resonant optical excitation in the p state of any of the quantum dots, results in an increase in the s-state emission of the other one. The cavity-mediated coupling can be controlled by varying the excitation intensity. These results represent an experimental step toward the realization of quantum logic operations using distant solid-state qubits.

The authors are indebted to E. Hu and R. Sabouni for helpful discussions. This work has been supported by research contracts of the Spanish Ministry of Education under Grants No. MAT2008-01555/NAN and Consolider No. CSD 2006-19 and Naninpho-QD under Grant No. TEC2008-06756-C03-01, and the Community of Madrid Grant CAM (Grant No. S2009/ESP-1503).

Peer reviewed